Comparative assessment of impact analysis methods applied to large commercial aircraft crash on reinforced concrete containment.

The precise evaluation of the potential damage caused by large commercial aircraft crash into civil structures, especially nuclear power plants (NPPs), has become essential design consideration. In this study, impact of Boeing 767 against rigid wall and outer containment building (reinforced concrete) of an NPP are simulated in ANSYS/LS-DYNA by using both force time history and missile target interaction methods with impact velocities ranging from 100 m/s to 150 m/s. The results show that impact loads, displacements, stresses for concrete and steel reinforcement, and damaged elements are higher in case of force time history method than missile target interaction method, making the former relatively conservative. It is observed that no perforation or scabbing takes place in case of 100 m/s impact speed, thus preventing any potential leakage. With full mass of Boeing 767 and impact velocity slightly above 100 m/s, the outer containment building can prevent local failure modes. At impact velocity higher than 120 m/s, scabbing and perforations are dominant. This concludes that in design and assessment of NPP structures against aircraft loadings, sufficient thickness or consideration of steel plates are essential to account for local failure modes and overall structural integrity. Furthermore, validation and application of detail 3D finite element and material models to full-scale impact analysis have been carried out to expand the existing database. In rigid wall impact analysis, the impact forces and impulses from FE analysis and Riera's method correspond well, which satisfies the recommendations of relevant standards and further ensure the accuracy of results in full-scale impact analysis. The methodology presented in this paper is extremely effective in simulating structural evaluation of full-scale aircraft impact on important facilities such as NPPs.

Clinical Features of Disaster-Associated Direct Deaths during Recent Inland Earthquakes in Japan.

Natural disasters, including earthquakes, cause disaster-associated direct deaths due to hazards and disaster-related deaths. This study was a retrospective and observational study that explored the effect of natural disasters on direct death. Although research reports on disaster-related deaths are common, there are few reports of disaster-associated direct death caused by events, such as house collapses, fires, and sediment-related factors. The amendment of the Building Standards Law in 1981 has made Japanese building standards more stringent. We sought to examine the determinants of the number of disaster-associated direct deaths during recent inland earthquakes in Japan. Following 2016 Kumamoto earthquakes (April 14, 21:26 [magnitude (M) 6.5], April 15, 0:03 [M 6.4], and April 16, 1:25 [M 7.3] and the subsequent numerous aftershocks), police necropsies confirmed 50 disaster-associated direct deaths (28 women [56%]). Thirty-four victims (68%) were elderly people 65 years of age or older, and 38 victims (76%) died as a result of a collapsed house. These percentages are consistent with those associated with recent inland earthquake disasters in Japan. The main finding was a linear correlation between the number of completely collapsed houses and the number of deaths due to house collapse during recent inland earthquakes in Japan (P = 0.02). It is suggested that the maintenance of houses may be important in reducing the number of disaster-associated direct deaths during inland earthquakes. The amendment of the Building Standards Law might reduce the number of disaster-associated direct deaths during inland earthquakes.

Emergency Department Ceiling Collapse: Response to an Internal Emergency.

Hospital disaster resilience is often conceived as the ability to respond to external disasters. However, internal disasters appear to be more common events in hospitals than external events. This report describes the aftermath of a ceiling collapse in the emergency department of VieCuri Medical Center in Venlo, the Netherlands, on May 18, 2017. By designating the acute medical unit as a temporary emergency department, standard emergency care could be resumed within 8 hours. This unique approach might be transferrable to other hospitals in the developed world. In general, it is vital that hospital disaster plans focus on both external and internal disasters, including specific scenarios that disrupt vital hospital departments such as the emergency department. (Disaster Med Public Health Preparedness. 2019;13:829-830).

Damage detection of structures identified with deterministic-stochastic models using seismic data.

A deterministic-stochastic subspace identification method is adopted and experimentally verified in this study to identify the equivalent single-input-multiple-output system parameters of the discrete-time state equation. The method of damage locating vector (DLV) is then considered for damage detection. A series of shaking table tests using a five-storey steel frame has been conducted. Both single and multiple damage conditions at various locations have been considered. In the system identification analysis, either full or partial observation conditions have been taken into account. It has been shown that the damaged stories can be identified from global responses of the structure to earthquakes if sufficiently observed. In addition to detecting damage(s) with respect to the intact structure, identification of new or extended damages of the as-damaged counterpart has also been studied. This study gives further insights into the scheme in terms of effectiveness, robustness, and limitation for damage localization of frame systems.

Stochastic landslide vulnerability modeling in space and time in a part of the northern Himalayas, India.

Little is known about the quantitative vulnerability analysis to landslides as not many attempts have been made to assess it comprehensively. This study assesses the spatio-temporal vulnerability of elements at risk to landslides in a stochastic framework. The study includes buildings, persons inside buildings, and traffic as elements at risk to landslides. Building vulnerability is the expected damage and depends on the position of a building with respect to the landslide hazard at a given time. Population and vehicle vulnerability are the expected death toll in a building and vehicle damage in space and time respectively. The study was carried out in a road corridor in the Indian Himalayas that is highly susceptible to landslides. Results showed that 26% of the buildings fall in the high and very high vulnerability categories. Population vulnerability inside buildings showed a value >0.75 during 0800 to 1000 hours and 1600 to 1800 hours in more buildings that other times of the day. It was also observed in the study region that the vulnerability of vehicle is above 0.6 in half of the road stretches during 0800 hours to 1000 hours and 1600 to 1800 hours due to high traffic density on the road section. From this study, we conclude that the vulnerability of an element at risk to landslide is a space and time event, and can be quantified using stochastic modeling. Therefore, the stochastic vulnerability modeling forms the basis for a quantitative landslide risk analysis and assessment.

A multiple additive regression tree analysis of three exposure measures during Hurricane Katrina.

This paper analyses structural and personal exposure to Hurricane Katrina. Structural exposure is measured by flood height and building damage; personal exposure is measured by the locations of 911 calls made during the response. Using these variables, this paper characterises the geography of exposure and also demonstrates the utility of a robust analytical approach in understanding health-related challenges to disadvantaged populations during recovery. Analysis is conducted using a contemporary statistical approach, a multiple additive regression tree (MART), which displays considerable improvement over traditional regression analysis. By using MART, the percentage of improvement in R-squares over standard multiple linear regression ranges from about 62 to more than 100 per cent. The most revealing finding is the modelled verification that African Americans experienced disproportionate exposure in both structural and personal contexts. Given the impact of exposure to health outcomes, this finding has implications for understanding the long-term health challenges facing this population.

Analysis of 46 maxillofacial fracture victims in the 2008 Wenchuan, China earthquake.

PURPOSE: At 14:28 hours on May 12, 2008, a massive earthquake wracked most areas of Sichuan, China, causing catastrophic human loss. The aim of this study was to delineate the characteristics of victims with maxillofacial fractures in this disaster. PATIENTS AND METHODS: A descriptive analysis was conducted based on the medical records of earthquake maxillofacial injuries casualties transferred to West China Hospital of Stomatology, Sichuan University, after the earthquake. Data regarding demographic details, psychological status, patterns, anatomic sites, etiology, concomitant injuries, and management of earthquake maxillofacial fractures were evaluated. RESULTS: A total of 46 maxillofacial fracture patients' records of 28 (60.9%) males and 18 (39.1%) females were included in this study, with peak incidence (32.6%) in the elderly age group (older than 50 years). The most common etiology of earthquake maxillofacial fractures was building collapse (71.7%). The mandible (65.2%) was the most frequent site of the maxillofacial fracture, followed by the zygomatic complex (21.7%) and maxilla (13.0%). The most prevalent of maxillofacial fracture pattern was multiple and/or comminuted fractures (56.5%), which accounted for 72.7% (24/33) in building collapse injury group. There were 9 (19.6%) patients with significant concomitant injuries and the most common site of concomitant injuries was the head (4 cases) and extremity (4 cases). Four (8.7%) patients' maxillofacial fractures were treated conservatively, 16 (34.8%) underwent closed reduction and fixation, and 26 (56.5%) underwent open reduction and rigid internal fixation (RIF). Apart from 3 patients (6.5%) who showed infection, all patients with facial fractures achieved successful bony union with an acceptable occlusion and facial form. Additionally, it is noteworthy that all patients in our study presented the symptoms of posttraumatic stress disorder (PTSD). CONCLUSION: There is a variation of mechanism of injuries, age group, severity, patterns, concomitant injuries, and management of earthquake maxillofacial fractures. Knowledge of these characteristics provides useful strategies for patient care and prevention of further complications. A multidisciplinary and coordinated approach is important for optimum stabilization and ongoing treatment of victims of building collapse injury. The high percentage of PTSD confirms that psychologists should form an integral part of this multidisciplinary team.

The association between roofing material and head injuries during the 2008 Wenchuan earthquake in China.

STUDY OBJECTIVE: We analyze the spectrum of earthquake-related head injuries resulting in hospitalization and arising from the 2008 Wenchuan Earthquake in China. An additional objective is to assess injury patterns associated with 2 types of roofing structures found in this region of China. METHODS: This descriptive study included data on trauma patients at 8 hospitals in Jiangyou for the 14 days immediately after the earthquake. The patients were either from Jiangyou County, which experienced a modified Mercalli intensity level of VIII, or from Beichuan County (Mercalli intensity level of X). Of the 5,775 earthquake-related injuries, 1,484 (25.7%) involved the head and were classified into 4 categories. Seven injury mechanisms were also analyzed to determine the association with the 4 types of head injuries. RESULTS: Scalp injuries (43%) were the most common type of head injuries, followed by facial injuries, 482 (32%), intracranial injuries, 218 (15%), and skull fractures, 117 (8%). Differences in injury type and cause were apparent, with scalp injuries being more common (49%) in Jiangyou than in Beichuan (30%) and falling clay tiles contributing more (40%) to this injury in the former city than the latter (6%). In contrast, precast concrete plank roofing caused 20% of scalp injuries in Beichuan compared with 3% in Jiangyou. CONCLUSION: Scalp injuries were the most common head injury type. Falling clay roofing tiles and precast concrete plank roofs are important injury mechanisms, and their contribution may reflect differences in building construction.